Knob



FIG. 1 is a perspective view of a knob showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof, the bottom view being a mirror image;

FIG. 4 is a right side elevational view thereof, the left side is a mirror image; and,

FIG. 5 is a rear view thereof.

The broken lines in the Figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a knob, as shown and described. 